1. Field of the Invention:
This invention relates to a process for the biological treatment in situ of wastewaters from factories in which animal and/or vegetable products are processed.
2. Statement of Related Art:
It is standard practice for wastewaters differing widely in composition to be mechanically and/or biologically cleaned in central treatment plants. Although central wastewater treatment processes can be operated very effectively, they are not optimally adapted to the requirements of the particular wastewater, require energy, and can be overloaded due to the large number of wastewater sources. In addition, central treatment plants have the disadvantage that, in the event of any failure, the entire wastewater stream has to be run off, inadequately treated, into receiving waters.
Accordingly, in the context of the increase in environmental awareness, discussions have recently centered around processes which enable special wastewaters to be pretreated in situ in decentral plants (so-called island solutions).
For example, dynamic bioreactors are well known among those skilled in the art (Prof. Brauer, Institut fur Chemie und Ingenieurtechnik der Techn. Universitat, Berlin). In bioreactors such as these, a lifting element fitted with perforated discs is reciprocated in a cylindrical vessel so that aerobic and anaerobic conditions can be established as required. Although very good treatment results are obtained in a confined space in this way, the presence of mechanically moving parts involves susceptibility to failure. In addition, the sequence of movements has to be controlled at considerable expense and, in the case of the aerobic variant, provision has to be made for the introduction of oxygen.
A so-called RMC separator bioreactor is described in a company booklet "Biologische Abwasserreinigung im Hochleistungsreaktor und Schwerkrafabscheider (Biological Wasterwater Treatment in a High Performance Reactor and Gravity Separator)" of NEBA GmbH & Co. KG, Postfach 1160, 6542 Heinburg 1. This reactor is, broadly speaking, a fat separator of the type commonly used in slaughterhouses and meat-processing factories which has been converted into an aerobic treatment system by addition of aerobic bacteria. The susceptibility to failure of this reactor and the relatively long regeneration times after a failure are disadvantages. In addition, because the reactor operates purely aerobically, the pollutants are largely converted into biomass which then has to be separated off in a following step or pollution of the drainage system results.